Can the category facet return all matching categories instead of a single level?

[aligent-lturner]

Is your question related to a problem? Please describe.
We have a requirement from a client that when performing a search, the category facet is displayed as a tree structure. We planned on doing that by comparing the returned category facets to a cached category tree and merging the two.
However, it appears that only a single level of categories is returned (the top level under the root categories) by the facet, regardless of the number of products.

My assumption is that this is intended so that customers can "drill down" themselves - if they filter by a top-level category, they would get the children of that category, etc.

But, Is there a way to make the category facet return all categories that have matching products (and ideally, exclude those with no results)?

[vahonc]

Hello @aligent-lturner,

My assumption is that this is intended so that customers can "drill down" themselves - if they filter by a top-level category, they would get the children of that category, etc.

Yes, this behavior is intentional and aligns with how ElasticSuite is designed to work. Category facets in ElasticSuite are hierarchical and contextual, meaning that only one level of categories is returned at a time, based on the current search context. This enables a "drill-down navigation" experience where users first see top-level categories and, once a category is selected, are then presented with its relevant subcategories. And this approach is widely used in search engines and is optimized for both usability and performance.

Returning all matching categories at all depths is technically possible, but it would require significantly more complex Elasticsearch aggregations, such as deep or recursive sub-aggregations, in order to compute product counts for every category in the tree and dynamically exclude empty ones. Especially if you will using virtual categories as the aggregation query for a single category that belongs to the physical category OR list of virtual children categories (anywhere in the tree) query, so I'm pretty sure that "max boolean clauses" error is almost guaranteed here. In results, this will lead to a noticeable performance cost, especially on large catalogs, increases memory usage, makes caching less efficient, and can lead to slower response times. For these reasons, ElasticSuite deliberately avoids this approach and focuses on returning only the most relevant category level at each step.

BR,
Vadym